In October 1962, the discovery of Soviet nuclear missiles on the island of Cuba brought the superpowers - the United States and the Soviet Union - to the brink of war. Having earlier warned Ottawa of increasing Soviet submarine activity before the crisis became public knowledge on 22 October, Dyer quickly cancelled all non-essential sailings and placed the fleet on a war footing. During and after the crisis, his ships conducted joint anti-submarine patrols with American forces.